Presently, various commercial and non commercial communication services allow exchanging of digital information packets between physically remote computers connected by an international network of servers using the public switched telephone network (PSTN) or any other communication network. Many commercial service providers also provide access to the Internet. An example of one type of use of such services which gained popularity lately is the Internet telephone. The Internet telephone is based on a combination of software and hardware which allows a user of a computer with access to the Internet to establish a vocal conversation link with another user's computer through the modems installed in both computers. After the establishment of an Internet link, the user speaks to a microphone which is connected to a sound card installed in the computer, the voice information is digitized, compressed and sent as digital information packets using the Internet's packet switching protocols to reach the other user's computer, where it is decompressed and converted to analog sound which the other user can listen to. Thus, for the price of a local telephone call, a user with access to the Internet can make unlimited long distance and international calls to other users which have Internet access. The recent availability of full duplex sound cards and the prospects of continuing improvements in speed, data carrying capacity and reliability of the services of many Internet service providers, makes Internet telephony attractive to many users.
A drawback of existing Internet telephony methods is the fact that in order to use them a user must establish an Internet connection and use the microphone and sound card installed in the computer, thus, the user must be near the computer.
An additional drawback of current Internet telephony methods is the fact that both users who are wishing to conduct a conversation must coordinate in advance a time slot during which both users will be seated by their computers after having established an Internet connection. Thus a user cannot establish a net telephone conversation with another user unless the other user is already connected to the Internet.
Similar disadvantages exist for users who want to exchange information using computers connected to a WAN.